Substance abuse and addiction are typically played for laughs on the CBS comedyMom, but that's not the case on Monday's "very special episode," in which Bonnie (Allison Janney) falls off the wagon. And she doesn't exactly have a soft landing."It's ...

TV Guide

Substance abuse and addiction are typically played for laughs on the CBS comedy Mom, but that's not the case on Monday's "very special episode," in which Bonnie (Allison Janney) falls off the wagon. And she doesn't exactly have a soft landing.

"It's quite a look I sport in this episode," Janney tells TVGuide.com. "No vanity involved in this performance!"

Joking aside, Janney says she was excited to explore Bonnie's rarely seen vulnerable side. "They allowed me to go to emotional places that you don't usually see on a half-hour sitcom, so I loved it," Janney says. "I think that we manage to find the humor in the adversity. ... I didn't have to search to find the comedy in the pain, because that felt to me very natural - trying to make jokes in the middle of a terrible life story. You've just got to laugh, which I love about Bonnie. She just tries to make a joke all the time, and it makes it kind of heartbreaking, and relatable too."

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Bonnie finally hits rock bottom after losing her job and her apartment, but viewers learn that she's been dabbling in her old ways for several weeks. "She was dealing with her sobriety with one foot in and one foot out ... not really committed 100 percent," Janney says. "She's been dipping a little bit here and there and kind of thinking that she could ride the edge. I think a lot of people with addictions think, 'I can control it. I can deal with it. I can do this and I can do that, and I can do it all.' And I think she realizes in this episode that she can't do it all, and she can't have one toe into her addiction and the rest of her body out. [The addiction] is going to win."

Though Bonnie's relapse has been hinted at in previous episodes (in a joking way), Janney says she learned about the story line just two days before they started filming. "I was surprised that it was coming so soon," she says. "I knew it probably would be coming, because of all the characters to relapse, it would probably make sense for Bonnie because I think that the writers have to be careful with Christy because she has the children."

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Now that Bonnie has moved back in with her daughter and grandchildren, their new living arrangement will undoubtedly be played for laughs. But Janney points out that Christy (Anna Faris) and her children also provide Bonnie with new motivation to stay on the wagon this time around. "I think she realizes that she could possibly lose them all if this continues," she says. "That's what saves her: wanting to have her daughter and her grandkids in her life, wanting to show up for them and admitting that she needs them. It's an important step in her growth as a person, as a character."

The episode also marks a turning point in Bonnie's relationships with her AA colleagues Marjorie (Mimi Kennedy) and Regina (Octavia Spencer). "I love how Bonnie finds an unlikely friendship and commonality with the two women that she despises most," Janney says. "I think she probably finds a new appreciation for them and doesn't feel so alone after hearing about their stories."

Mom airs Mondays at 9:30/8:30c on CBS. Check out a sneak peek from Monday's episode below: